New Brain Study Questions Existence of “Sexual Addiction"

There is a lot of interest in the question of if too much sex, sexual desire, masturbation, or viewing of pornography is an addiction like to alcohol or cocaine. In fact, an early version of the new DSM-V manual of mental disorders included a “hypersexuality” diagnosis, but this diagnosis was not included in the finalized version. One tool to study addiction is to look at how the brain responds to those substances or cues of those substances. Until recently, this neuroscience approach had not been used to study hypersexuality. A new study published in the journal Socioaffective Neuroscience & Psychology has tested the brain’s response to sexual stimuli among a group of individuals who identified as having problems controlling their use of online pornography. This new study was published by my colleague (and fellow Indiana University Psychology alumni)Dr. Nicole Prause, who is an Assistant Research Scientist in the Department of Psychiatry at the University of California- Los Angeles and a Research Scientist at the Mind Research Network. Below are her answers to my questions about this new study.

What was the purpose of the study?

Some clinicians describe patients who report problems decreasing their sexual behaviors, such as viewing many hours of sexual films online every day, as sexually “addicted” or “hypersexual”. Our study tested whether people who report such problems look like other addicts from their brain responses to sexual images. Studies of drug addictions, such as cocaine, have shown a consistent pattern of brain response to images of the drug of abuse, so we predicted that we should see the same pattern in people who report problems with sex if it was, in fact, an addiction.

What is the main finding in your study?

We found that the brain’s response to sexual pictures was not predicted by any of three different questionnaire measures of hypersexuality. Brain response was only predicted by a measure of sexual desire. In other words, hypersexuality does not appear to explain brain differences in sexual response any more than just having a high libido.

If our study is replicated, these findings would represent a major challenge to existing theories of sex “addiction”. The reason these findings present a challenge is that is shows their brains did not respond to the images like other addicts to their drug of addiction.

What exactly did your study do?

A large group of men and women attracted to the opposite sex who reported having problems controlling their viewing of sexual images had their brain responses measured using electroencephalography (EEG) while they viewed photographs. These photographs were carefully selected from a well-characterized set of images to evoke pleasant or unpleasant feelings. Some pictures included dismembered bodies, people preparing food, skiers, and sex.1 The sexual images included some romantic images of caressing, kissing and undressing, whereas others showed explicit intercourse between one man and one woman. We were most interested in the brain’s response starting about 300 milliseconds after the picture appeared, which is commonly called the “P300”. This basic protocol and measure have been used in hundreds of neuroscience studies internationally, including studies of addiction and impulsivity, and we followed the same standards for collecting and analyzing these data. For example, one study of heroin dependent men reported increased P300 response to images of heroin as compared to neutral images.2

What was your hypothesis?

We hypothesized that the P300 response to the sexual images would be predicted by a person’s sexual desire level, as this has already been reported by other scientists. We also predicted that measures of hypersexuality might relate positively or negatively to the P300. The direction (positive or negative) would depend on which model of hypersexuality (addiction or impulsivity) was a better model.

What does it mean that P300 and hypersexual measures were not related?

It suggests that hypersexuality explains nothing in particular about brain responses to erotica. It also might mean that the relationship is so small that we were not able to see it with our measures.

What is EEG and why did you use it?

There are many ways to measure brain responses. MRI and EEG are very common. We choose measures depending on what we want to study. While fMRI is better for finding where something is occurring in the brain, EEG is better for finding when something is occurring in the brain. EEG measures synchronous firing activity (some have estimated of 100,000 neurons) at the scalp. EEG can be used to make pretty brain pictures like fMRI, and fMRI can be speeded, but there are good reasons to have both tools.

I thought there were already brain studies of sex addiction?

Surprisingly, no one has previously examined their brain in action. A few research groups included “porn addicts” in brain imaging studies of internet use problems, but none of those researchers actually analyzed the sex group separately. A couple of research groups published small structural brain studies, which means images of the brain when it is not doing anything in particular. We have colleagues in Germany who are currently writing the first fMRI results of their hypersexual patients, so anticipate more research in this area soon.

Who volunteered for your study?

Our ethics board was very concerned that, if we recruited people actually seeking treatment for sex addiction, showing them sexual images could cause them to “relapse”. We agreed to recruit people who reported problems regulating their viewing of visual sexual stimuli. We confirmed that they had problems with three questionnaires that are commonly used to measure hypersexuality. In the end, our volunteers actually reported just as many problems as patient samples.

How do these volunteers compare to people who do not have problems? A control group?

This study only included people who reported problems, ranging from relatively minor to overwhelming problems, controlling their viewing of visual sexual stimuli. This means we used a within-subject design. A within-subject design means people serve as their own control. Within-subject designs can be a much more powerful design, statistically and theoretically, than having a separate control group. For example, with a separate group, you have to make sure the only ways the groups differ from one another was on hypersexuality. This is very difficult to do given that many studies show that those who score high on hypersexual measures tend to score high on many other measures, for example, of emotional problems.

Why did you show people pictures? Don’t most people who use porn watch sex films online?

There were many reasons to use pictures, but a major reason was to parallel previous research related to our hypotheses. This type of research, sometimes called “cue reactivity” research, studies complicated processes by breaking them down to their most basic, early responses. Like cue-reactivity research in substance addictions, the images provide a glimpse of the brain’s earliest response to a relevant (e.g., sexual) cue without allowing the person to actually act (e.g., masturbate, select the next image) on the cue as they normally might. A similar study, for instance, shows cocaine addicts pictures of cocaine without allowing them to use cocaine.

What about sex addicts who visit prostitutes or cheat?

We did not study those individuals. The overwhelming majority of people seeking treatment for sex addiction report that their only, or main, problem is their frequency of viewing sexual images.

Who funded this study?

This study was supported by a grant from the Idaho State University, Graduate Student Research and Scholarship Committee awarded to Cameron Staley, Ph.D., for his dissertation research. These grants are competitive and are awarded based on the merit of the science. He also won an award for this research from the International Academy of Sex Research.

What does this mean for those in treatment for sex addiction now?

Nothing. The study needs to be replicated. Alternative explanations need to be explored. If the wrong model is currently being used to provide treatments, we must find the right model to help people struggling with their sexual behaviors. We’re working on it!

How can I read the study myself?

The Socioaffective Neuroscience of Psychology journal is an open access journal. You can access it here.

I was eager to read this article to look at a different perspective on the Sexual Addiction debate. It is very exciting to see that there have been attempts at studying the neural responses to sexually stimulating images. I look forward to more research of the brain "in action" especially in lieu of the ongoing debate of Sexual Addiction and its inclusion into the DSM-V criteria.

One immediate question about this study is whether the use of sexual images as triggers is the same as showing people drugs/drug paraphenalia to test for addiction.

The question is whether the sexual images are sating the cravings rather than merely triggering them. A better parallel for images of drug paraphenalia to test for "porn addiction" could be the outside of a sex-shop, or even a porn video loading on the internet.

Effectively the viewing of sexual images amongst heavy users of pornography might be the end goal of their addiction. It is success. The viewing of drugs is not the end goal but a tantalising reminder of the end goal. Hence the study does not compare the same things in regard to their hypothetical addiction.

I don't think showing the images is a big problem. The end goal of the experience is fapping to the images. The images are triggers for the experience of fapping to the images. In other words, show me a guy who repeatedly and extendedly looks at porn without fapping and you're showing me a statue.

What I liked best about this interview is how humble Prouse is about the potential results. She is all about scientific method, null hypothesis, and the importance of replication.

I think I have missed something here.
The post questions the existence of 'sexual addiction' and about 2/3 of the way through the interview, the following question is asked by Brian Mustanski:
"What about sex addicts who visit prostitutes or cheat?" The question speaks for itself, particularlly when contrasted by a previous questions which talks about volunteers (people who have problems) compared to people who do not have problems?
To use a sledgehammer here, it is possible to use neutral terminology - people, people who have problems, people who report having problems etc etc in an interview questioning the concept of sexual addiction. Yet Brian Mustanski refers to sex addicts as extant entities. A kinda post hoc ergo propter hoc fait accompli. Typical Latin French tomfoolery! What would that old, dusty, white, insignificant, male fool, Freud, have made of the fact that in an article whose raison d'être is the questioning of sexual addiction, the very subject of the study is called by the moniker whose existence is being questioned?
If you get my drift.
No more to say. After phoning my wife, I'm off to visit my local brothel after which a quickie with my mistress. I am/am not/or maybe could be a sex addict. Or not.

From Carnes (1983) all the way to the Sexual Recovery Institute treatment materials, they all draw direct parallels with substance abuse. I agree, this is completely moronic, and now we have some actual data to suggest one way in which the addiction model truly does not fit these problems.

The entire concept of "addiction" has always been so loaded with fundamentalist xtian ideologies of sin and redemption that I can't even find where science is supposed to find a foothold. How does one even define self-control or the lack of it without resorting to quasi-moral truisms?

Whether it's substance use, gambling, eating, sexual behavior or any other "addictive" behavior, there needs to be some serious rethinking of all the terms and concepts being tossed about. Otherwise, people are just pasting the name "science" on top of a script that was written in the 1830s.

Mustanski asks, "What was the purpose of the study?" And Prause replies, "Our study tested whether people who report such problems [problems with regulating their viewing of online erotica] look like other addicts from their brain responses to sexual images."

But the study did not compare brain recordings from persons having problems regulating their viewing of online erotica to brain recordings from drug addicts and brain recordings from a non-addict control group, which would have been the obvious way to see if brain responses from the troubled group look more like the brain responses of addicts or non-addicts.

Instead, Prause claims that their within-subject design was a better method, where research subjects serve as their own control group. With this design, they found that the EEG response of their subjects (as a group) to erotic pictures was stronger than their EEG responses to other kinds of pictures. This is shown in the inline waveform graph (although for some reason the graph differs considerably from the actual graph in the published article).

So this group who reports having trouble regulating their viewing of online erotica has a stronger EEG response to erotic pictures than other kinds of pictures. Do addicts show a similarly strong EEG response when presented with their drug of choice? We don't know. Do normal, non-addicts show a response as strong as the troubled group to erotica? Again, we do not know. We don't know whether this EEG pattern is more similar to the brain patterns of addicts or non-addicts.

The Prause research team claims to be able to demonstrate whether the elevated EEG response of their subjects to erotica is an addictive brain response or just a high-libido brain response by correlating a set of questionnaire scores with individual differences in EEG response. But explaining differences in EEG response is a different question from exploring whether the overall group's response looks addictive or not. The Prause group reported that the only statistically significant correlation with the EEG response was a negative correlation (r=-.33) with desire for sex with a partner. In other words, there was a slight tendency for subjects with strong EEG responses to erotica to have lower desire for sex with a partner. How does that say anything about whether the brain responses of people who have trouble regulating their viewing of erotica are similar to addicts or non-addicts with a high libido?

It appears that the journal in which the source article was published is not a PubMed indexed journal. This always makes me suspicious since there are a number of open source journals which will publish your laundry list if you pay them enough. Is this a reputable journal?

Yes, Socioaffective Neuroscience and Psychology is a peer-reviewed journal, not a pay-for-play. It is relatively new, so they have not yet pursued (as far as I know) impact factor rankings yet. As all the article authors have plenty of pubs in IF-rated journals too, this was probably a requested, peer-reviewed manuscript.

Below is one of many articles covering a new study by Cambridge University.

Pornography addiction leads to same brain activity as alcoholism or drug abuse, study shows
Cambridge University scientists reveal changes in brain for compulsive porn users which don't occur in those with no such habit

The above study contradicts claims made in the Prause study and related press. I say 'claims,' because the Prause study actually found increased arousal when subjects viewed porn, even though she characterized her study as not finding arousal to sexual images in this quote - PRAUSE: "The reason these findings present a challenge is that it shows their brains did not respond to the images like other addicts to their drug of addiction."

Actually, P300 readings were higher for porn images than for neutral images, which is exactly what would be expected for someone with an addiction.

On to the new study. The Cambridge study also examined cue-induced reaction, but did so in a standard, scientific manner. Thus it differs greatly in its design methodology as compared with Prause's effort.

Prause's only legitimate claim was that she found no correlations between questionnaire scores and EEG readings. This was to be expected, and is therefore meaningless. She used a heterogeneous group of subjects but showed them all the same images. That is, she recruited males, females, and 7 non-heterosexuals, yet they all viewed vanilla heterosexual sex.

1) Unlike the Prause study, the Cambridge used brain scans (fMRI) to assess the activity of the reward center (ventral stritaum), where cue reaction occurs with spikes of dopamine. This proceedure is well established and has been employed in dozens of Internet addiction and other addiction studies. In contrast, Prause measured EEGs, which only assess electrical activity of the cerebral cortex, and are open to wide interpretation.

2) Unlike the Prause study, the Cambridge study used a homogenous group of subjects: young, heterosexual males.

3) From what I understand, the Cambridge study matched subjects with their preferred genres of porn. This is the key difference between the Prause study and is one of several reasons she found no correlation with the questionnaires she administered. You can't show a gay person straight porn (as she did) and expect the meaningful results (Prause included 7 non-heterosexuals). More to the point, porn addicts have often escalated to certain genres they now find arousing, while old genres are relatively boring. For accurate results, a study must match porn genre to each subject.

4) Unlike the Prause study, the Cambridge study scanned the brains of matched controls. The Prause study had no control group. To this day Prause has no idea what normal EEG readings would have been for her subjects, yet she made far-reaching claims all over the press that her work unravels the concept of sex addiction. Unbelievable.

- PRAUSE: "If our study is replicated, these findings would represent a major challenge to existing theories of sex “addiction”

Replicating a study that is deeply flawed will not challenge anything.

My mind still boggles at the Prause claim that her subjects' brains did not respond to sexual images like drug addicts' brains respond to their drug, given that she reports higher P300 readings for the sexual images. Just like addicts who show P300 spikes when presented with their drug of choice.